The effect of screening for vaccine hesitancy on the subsequent development of hesitancy: a randomized controlled trial, Houston, TX

Figures & data

Figure 1. Enrollment flow chart

Table 1. Proportion (%) of baseline participant characteristics by randomization group*

	Placebo	PACV
	N = 863	N = 842
	N (%)	N (%)	p-value
First baby			0.376
Yes	346 (40.2)	357 (42.4)
No	514 (59.8)	485 (57.6)
Missing	3	0
Relationship to child			0.946
Mother	793 (92.2)	774 (91.9)
Father	65 (7.6)	66 (7.8)
Other	2 (0.2)	2 (0.2)
Missing	3	0
Age			0.406
18–29	365 (42.4)	374 (44.5)
≥30	495 (57.6)	467 (55.5)
Missing	3	1
Marital status			0.229
Single	107 (12.4)	117 (13.9)
Married	662 (76.8)	653 (77.6)
Living with a Partner	80 (9.3)	65 (7.7)
Other	13 (1.5)	6 (0.7)
Missing	1	1
Education			0.396
Some college or less	358 (41.5)	375 (44.5)
4-year college degree	285 (33.0)	271 (32.2)
>4-year college degree	220 (25.5)	196 (23.3)
Missing	0	0
Household income			0.650
$30,000 or less	151 (18.2)	146 (18.0)
$30,001–50,000	101 (12.2)	112 (13.8)
$50,0001–75,000	119 (14.4)	126 (15.5)
$75,001 or more	457 (55.2)	428 (52.7)
Missing	35	30
# of children in household			0.334
1	324 (37.6)	335 (39.8)
2	328 (38.1)	293 (34.8)
3	146 (16.9)	137 (16.3)
4 or more	64 (7.4)	77 (9.1)
Missing	1	0 (0.0)
Race/Ethnicity			0.340
White	394 (45.8)	400 (47.7)
Black	154 (17.9)	127 (15.2)
Hispanic	185 (21.5)	181 (21.6)
Asian	73 (8.5)	63 (7.5)
Other	54 (6.3)	67 (8.0)
Missing	3	4

*Due to rounding, percentages may not add up to 100.

Table 2. Proportion (%) of baseline participant characteristics by follow up status*

	Lost to follow up	Completed 6 month follow up
	N = 886	N = 819
	N (%)	N (%)	p-value
Randomization group			0.073
Placebo	467 (52.7)	396 (48.4)
PACV	419 (47.3)	423 (51.6)
First baby			0.522
Yes	372 (42.1)	331 (40.5)
No	512 (57.9)	487 (59.5)
Missing	2	1
Relationship to child			0.150
Mother	808 (91.4)	759 (92.8)
Father	72 (8.1)	59 (7.2)
Other	4 (0.5)	0 (0.0)
Missing	2	1
Age			0.004
18–29	413 (46.8)	326 (39.8)
≥30	469 (53.2)	493 (60.2)
Missing	4	0
Marital status			<0.001
Single	146 (16.5)	78 (9.5)
Married	630 (71.3)	685 (83.6)
Living with a Partner	96 (10.9)	49 (6.0)
Other	12 (1.4)	7 (0.9)
Missing	2	0
Education			<0.001
Some college or less	436 (49.2)	297 (36.3)
4-year college degree	281 (31.7)	275 (33.6)
>4-year college degree	169 (19.1)	247 (30.2)
Missing	0	0
Household income			<0.001
$30,000 or less	177 (21.0)	120 (15.1)
$30,001–50,000	125 (14.8)	88 (11.0)
$50,001–75,000	142 (16.8)	103 (12.9)
$75,001 or more	399 (47.3)	486 (61.0)
Missing	43	22
# of children in household			0.115
1	343 (38.8)	316 (38.6)
2	306 (34.6)	315 (38.5)
3	151 (17.1)	132 (16.1)
4 or more	85 (9.6)	56 (6.8)
Missing	1	0
Race/Ethnicity			<0.001
White	356 (40.3)	438 (53.7)
Black	175 (19.8)	106 (13.0)
Hispanic	210 (23.8)	156 (19.1)
Asian	79 (8.9)	57 (7.0)
Other	63 (7.1)	58 (7.1)
Missing	3	4

*Due to rounding, percentages may not add up to 100.

Table 3. Proportion of vaccine-hesitant parents (VHPs) by randomization group and study time point

Study time point and randomization group	Total N	VHPs N (%)	95% CI
Baseline*
PACV (lost to follow up)	419	28 (6.7)	4.5–9.5
PACV (completed 6-month follow up)	423	40 (7.1)	4.8–10.0
PACV (all participants)	842	58 (6.9)	5.3–8.8
6 months^+
PACV (randomized to PACV group; completed 6-month follow up)	423	28 (6.6)	4.4–9.4
Placebo (randomized to placebo group; completed 6 month follow up)	396	24 (6.1)	3.9–8.9
PACV + placebo (all participants who completed 6-month follow up)	819	53 (6.4)	4.8–8.2

*The proportion of VHPs is based on PACV score data at baseline.

+The proportion of VHPs at 6 months is based on PACV score data at 6-month follow up.

Table 4. The odds of vaccine hesitancy (i.e. scoring ≥50 on the PACV) at 6-month follow-up

	Independent		Multivariable*
	OR (95% CI)	p-value	OR (95% CI)	p-value
PACV group	1.10 (0.63–1.93)	0.743	1.13 (0.64–2.01)	0.675
First baby	0.91 (0.51–1.63)	0.761	-
Mother	1.29 (0.39–4.26)	0.678	-
≥30 years	1.06 (0.60–1.89)	0.838	-
Marital status		0.167
Single	Reference		-
Married	0.59 (0.27–1.30)	0.187	-
Other	0.16 (0.02–1.31)	0.088
>$50,000	0.55 (0.30–1.00)	0.051	-
Households with ≥2 children	0.92 (0.52–1.64)	0.783	-
Race/Ethnicity		0.003		0.003
White	Reference		Reference
Black Hispanic	3.02 (1.48–6.16) 1.07 (0.47–2.48)	0.002 0.868	3.06 (1.50–6.27) 1.08 (0.47–2.50)	0.002 0.854
Asian	0.35 (0.05–2.69)	0.316	0.36 (0.05–2.71)	0.319
Other	3.18 (1.34–7.55)	0.009	3.16 (1.33–7.52)	0.009
Education		0.390	-
Some college or less	Reference		-
4-year college degree	0.79 (0.41–1.50)	0.465	-
>4-year college degree	0.61 (0.30–1.25)	0.179

*Race/ethnicity and randomization group were only characteristics included in the multivariable model.